Forensic firearm examiners have to match fired bullets and cartridges under analysis with bullets and cartridges known to be fired by specific weapons. For so doing, examiners search for similarities between ammunition and weapons suspected to have been employed in the firing. According to the usual manual process, two bullets or two cartridges are placed under a comparison microscope, and the bullets or cartridges are viewed at the same time by the examiner who compares the characteristics of their outer surfaces to determine if there is a match between them. As the reason for determining whether there is or is not a match is to present evidence in legal proceeding, the final step in the determination is normally performed by a human being who can subsequently appear as a witness in the legal proceeding. Nevertheless, the burden of examiner could be greatly alleviated by an automated system for providing degree of match between pairs of bullets or cartridges. Such an automated system is disclosed in U.S. Pat. No. 5,379,106 issued on Jan. 3, 1995 to the Applicant, which system comprises a microscope aligned with a bullet to be examined and being coupled to a video camera sending image electrical signals to an image digitizer to produce a digital representation of the bullet outer surface. The coded digital representations of the bullet can then be computer compared to the coded digital representation of another bullet to determine if there is a match between the bullets. The system comprises a bullet carrier provided with a rotating rod coupled to a motor and a support rod, each having and inner end affixed to a respective end of the bullet to provide support and rotation thereof. For the purposes of forensic examination, there is generally required to accurately adjust the position of the bullet mounted on the carrier. Although such positioning can be assisted by monitoring apparatus as taught in the U.S. 5,379,106 patent, which uses a pair of light sources directing planar light beams at angle on the outer surface of the bullet under observation for providing indication of the position of the bullet as held on the carrier, manipulation of the bullet by the examiner to obtain a desired position may delay the examining task, especially when a plurality of bullets have to be analyzed.
Another prior art bullet mounting device is disclosed in U.S. Pat. No. 3,780,614 issued on Feb. 5, 1973 to Maier, which mounting device comprises a plurality of bullet holders rotatably connected to a rotatable carrier, and a manually retractable shaft provided with an end blade adapted to engage a selected bullet holder while allowing rotation thereof about its longitudinal axis, to index the carrier and to releasably hold the carrier in position. Although such multiple mounting device can handle a plurality of bullets to perform a corresponding series of inspection routines, manipulation of each bullet by the examiner to obtain a particular position may be still difficult and time-consuming, especially where the bullet under inspection is damaged or where both bullets and cartridges have to be successively examined.
In U.S. Pat. No. 5,654,801 issued on Aug. 5, 1997 to the Applicant, there is disclosed an automated fired ammunition imaging apparatus provided with bullet and cartridge mounting devices and associated microscope and camera assemblies.
In International application NO. WO 97/21128 published on Jun. 12, 1997 and naming the Applicant as Assignee, there is disclosed a portable apparatus for imaging fired cartridges.
There is still a need for a compact fired ammunition imaging apparatus providing improved manipulation features.